Base station Wikipedia. Base station or base radio station is according to the International Telecommunication Unions ITU Radio Regulations RR1 a land station in the land mobile service. The term is used in the context of mobile telephony, wireless computer networking and other wireless communications and in land surveying. In surveying, it is a GPS receiver at a known position, while in wireless communications it is a transceiver connecting a number of other devices to one another andor to a wider area. In mobile telephony, it provides the connection between mobile phones and the wider telephone network. In a computer network, it is a transceiver acting as a router for computers in the network, possibly connecting them to a local area network andor the internet. In traditional wireless communications, it can refer to the hub of a dispatch fleet such as a taxi or delivery fleet, the base of a TETRA network as used by government and emergency services or a CBshack. Land surveyingeditIn the context of external land surveying, a base station is a GPS receiver at an accurately known fixed location which is used to derive correction information for nearby portable GPS receivers. This correction data allows propagation and other effects to be corrected out of the position data obtained by the mobile stations, which gives greatly increased location precision and accuracy over the results obtained by uncorrected GPS receivers. Computer networkingeditIn the area of wireless computer networking, a base station is a radio receivertransmitter that serves as the hub of the local wireless network, and may also be the gateway between a wired network and the wireless network. It typically consists of a low power transmitter and wireless router. Wireless communicationseditIn radio communications, a base station is a wireless communications station installed at a fixed location and used to communicate as part of one of the following Two way radioeditProfessionaleditIn professional two way radio systems, a base station is used to maintain contact with a dispatch fleet of hand held or mobile radios, andor to activate one way paging receivers. Download Base Transceiver Station Pdf' title='Download Base Transceiver Station Pdf' />The base station is one end of a communications link. The other end is a movable vehicle mounted radio or walkie talkie. Examples of base station uses in two way radio include the dispatch of tow trucks and taxicabs. Basic base station elements used in a remote controlled installation. Selective calling options such as CTCSS are optional. Professional base station radios are often one channel. In lightly used base stations, a multi channel unit may be employed. In heavily used systems, the capability for additional channels, where needed, is accomplished by installing an additional base station for each channel. Each base station appears as a single channel on the dispatch center control console. Base+Transceiver+Station+%28BTS%29.jpg' alt='Download Base Transceiver Station Pdf' title='Download Base Transceiver Station Pdf' />In a properly designed dispatch center with several staff members, this allows each dispatcher to communicate simultaneously, independently of one another, on a different channel as necessary. For example, a taxi company dispatch center may have one base station on a high rise building in Boston and another on a different channel in Providence. Each taxi dispatcher could communicate with taxis in either Boston or Providence by selecting the respective base station on his or her console. In dispatching centers it is common for eight or more radio base stations to be connected to a single dispatching console. Dispatching personnel can tell which channel a message is being received on by a combination of local protocol, unit identifiers, volume settings, and busy indicator lights. A typical console has two speakers identified as select and unselect. Audio from a primary selected channel is routed to the select speaker and to a headset. A base transceiver station BTS is a piece of equipment that facilitates wireless communication between user equipment UE and a network. UEs are devices like. View and Download Galaxy DX 2517 owners manual online. AM FM SSB CW PA Amateur Base Station Transceiver. DX 2517 Radio pdf manual download. AIRCRAFT SPRUCE CATALOG PDF DOWNLOAD To view the files youll need the Adobe Acrobat reader. If you dont have the Adobe reader, you can download it. ELECTRONICS AND COMMUNICATION Engineering Questions and Answers PDF free download,ece interview questions with answers pdf,ece OBJECTIVE Lab Viva Mcqs. Each channel has a busy light which flashes when someone talks on the associated channel. Base stations can be local controlled or remote controlled. Local controlled base stations are operated by front panel controls on the base station cabinet. Remote control base stations can be operated over tone or DC remote circuits. The dispatch point console and remote base station are connected by leased private line telephone circuits, sometimes called RTO circuits, a DS 1, or radio links. The consoles multiplex transmit commands onto remote control circuits. Some system configurations require duplex, or four wire, audio paths from the base station to the console. Others require only a two wire or half duplex link. The diagram shows a band pass filter used to reduce the base station receivers exposure to unwanted signals. It also reduces the transmission of undesired signals. The isolator is a one way device which reduces the ease of signals from nearby transmitters going up the antenna line and into the base station transmitter. Manual De Cocinar En Microondas Faciles Para more. This prevents the unwanted mixing of signals inside the base station transmitter which can generate interference. Interference could be defined as receiving any signal other than from a radio in your own system. To avoid interference from users on the same channel, or interference from nearby strong signals on another channel, professional base stations use a combination of 89minimum receiver specifications and filtering. US, coordination of shared frequencies by coordinating agencies. Base stations are sometimes called control or fixed stations in US Federal Communications Commission licensing. These terms are defined in regulations inside Part 9. In US licensing jargon, types of base stations include A fixed station is a base station used in a system intended only to communicate with other base stations. A fixed station can also be radio link used to operate a distant base station by remote control. No mobile or hand held radios are involved in the system. A control station is a base station used in a system with a repeater where the base station is used to communicate through the repeater. A temporary base is a base station used in one location for less than a year. A repeater is a type of base station that extends the range of hand held and mobile radios. Amateur and hobbyist useeditIn amateur radio, a base station also communicates with mobile rigs but for hobby or family communications. Amateur systems sometimes serve as dispatch radio systems during disasters, search and rescue mobilizations, or other emergencies. An Australian. UHF CB base station is another example of part of a system used for hobby or family communications. Wireless telephoneeditWireless telephone differ from two way radios in that wireless telephones are circuit switched the communications paths are set up by dialing at the start of a call and the path remains in place until one of the callers hangs up. A wireless telephone base station communicates with a mobile or hand held phone. For example, in a wireless telephone system, the signals from one or more mobile telephones in an area are received at a nearby base station, which then connects the call to the land line network. Other equipment is involved depending on the system architecture. Mobile telephone provider networks, such as European GSM networks, may involve carrier, microwave radio, and switching facilities to connect the call. In the case of a portable phone such as a US cordless phone, the connection is directly connected to a wired land line. Emissions issuesedit. A cell tower near Thicketty, South Carolina. TOP ELECTRONICS and COMMUNICATION Engineering Questions and Answers PDF ECE Questions and Answers PDFCLICK HERE ECE MCQs. CLICK HERE Basic ELECTRONICS Questions. Expand ECE Electronics Communication Engineering. What is ElectronicThe study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles. What is communication Communication means transferring a signal from the transmitter which passes through a medium then the output is obtained at the receiver. ECE Interview Questions. Different types of communications Explain. Analog and digital communication. As a technology, analog is the process of taking an audio or video signal the human voice and translating it into electronic pulses. Digital on the other hand is breaking the signal into a binary format where the audio or video data is represented by a series of 1s and 0s. Broadcom 802.11 Network Adapter Wireless Driver Windows 7. Digital signals are immune to noise, quality of transmission and reception is good, components used in digital communication can be produced with high precision and power consumption is also very less when compared with analog signals. Define What is engineeringThe application of science to the needs of humanity and a profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to use economically the materials and forces of nature for the benefit of mankind. Difference between electronic and electrical. Electronics work on DC and with a voltage range of 4. DC to 4. 8v. DC. If the electronic device is plugged into a standard wall outlet, there will be a transformer inside which will convert the AC voltage you are supplying to the required DC voltage needed by the device. Examples Computer, radio, T. V, etcElectric devices use line voltage 1. AC, 2. 40v. AC, etc. Electric devices can also be designed to operate on DC sources, but will be at DC voltages above 4. Examples are incandescent lights, heaters, fridge, stove, etc7. What is sampling The process of obtaining a set of samples from a continuous function of time xt is referred to as sampling. State sampling theorem. It states that, while taking the samples of a continuous signal, it has to be taken care that the sampling rate is equal to or greater than twice the cut off frequency and the minimum sampling rate is known as the Nyquist rate. What is pass band Passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated. What is stop band A stopband is a band of frequencies, between specified limits, in which a circuit, such as a filter or telephone circuit, does not let signals through, or the attenuation is above the required stopband attenuation level. Difference between mobile and a cell phone. There is no difference, just language use, which differs from country to country, so in Britain it is called a mobile, and in USA and South Africa and other places a cell phone. Even in Europe the name differs. The Germans call it a handy, which in English has completely another meaning as an adjective, meaning useful. In Italy it is called a telofonino or little phone. This difference in British and American English is also evident in many other things we use every day, like lifts and elevators, nappies and diapers, pickups and trucks. The list goes on and on, any student of English has to decide which he or she will use, as the default setting. Explain RF Radio frequency RF is a frequency or rate of oscillation within the range of about 3 Hz to 3. GHz. This range corresponds to frequency of alternating current electrical signals used to produce and detect radio waves. Since most of this range is beyond the vibration rate that most mechanical systems can respond to, RF usually refers to oscillations in electrical circuits or electromagnetic radiation. What is modulation And where it is utilized Modulation is the process of varying some characteristic of a periodic wave with an external signals. Radio communication superimposes this information bearing signal onto a carrier signal. These high frequency carrier signals can be transmitted over the air easily and are capable of travelling long distances. The characteristics amplitude, frequency, or phase of the carrier signal are varied in accordance with the information bearing signal. Modulation is utilized to send an information bearing signal over long distances. Define what is demodulation Demodulation is the act of removing the modulation from an analog signal to get the original baseband signal back. Demodulating is necessary because the receiver system receives a modulated signal with specific characteristics and it needs to turn it to base band. Name the modulation techniques. For Analog modulationAM, SSB, FM, PM and SMDigital modulationOOK, FSK, ASK, Psk, QAM, MSK, CPM, PPM, TCM, OFDM1. Explain AM and FM. AM Amplitude modulation is a type of modulation where the amplitude of the carrier signal is varied in accordance with the information bearing signal. FM Frequency modulation is a type of modulation where the frequency of the carrier signal is varied in accordance with the information bearing signal. AM and FM AM is used for video signals for example TV. Ranges from 5. 35 to 1. Hz. FM is used for audio signals for example Radio. Ranges from 8. 8 to 1. MHz. 1. 8. How does a mobile work When you talk into a mobile telephone it converts the sound of your voice to radiofrequency energy radio waves. The radio waves are transmitted through the air to a nearby base station. The base station then sends the call through the telephone network until it reaches the person you are calling. When you receive a call on your mobile phone the message travels through the telephone network until it reaches a base station near to you. The base station sends out radio waves, which are detected by your telephone and converted back to speech. Depending on the equipment and the operator, the frequency that each operator utilises is 9. MHz, 1. 80. 0MHz or 2. MHz. The mobile phone network operates on the basis of a series of cells. Each cell requires a radio base station to enable it to function. There are three types of base station and each has a particular purpose The Macrocell is the largest type and provides the main coverage for mobile phone networks. The Microcell is used to improve capacity in areas where demand to make calls is high, such as shopping centres. The Picocell only has a range of a few hundred metres and may be used to boost weak signals within large buildings. Each base station can only cope with a certain number of calls at any one time. So if demand exceeds the capacity of a base station an additional base station is needed. What is a base stationBase station is a radio receivertransmitter that serves as the hub of the local wireless network, and may also be the gateway between a wired network and the wireless network. How many satellites are required to cover the earth The life span of the satellite is about 1. What is a repeaterA repeater is an electronic device that receives a signal and retransmits it at a higher level andor higher power, or onto the other side of an obstruction, so that the signal can cover longer distances without degradation. What is attenuationAttenuation is the reduction in amplitude and intensity of a signal.